21 files changed, 1086 insertions, 163 deletions

diff --git a/t/perf/README b/t/perf/README
index 21321a0f36..be12090c38 100644
--- a/t/perf/README
+++ b/t/perf/README
@@ -168,3 +168,28 @@ that
   While we have tried to make sure that it can cope with embedded
   whitespace and other special characters, it will not work with
   multi-line data.
+
+Rather than tracking the performance by run-time as `test_perf` does, you
+may also track output size by using `test_size`. The stdout of the
+function should be a single numeric value, which will be captured and
+shown in the aggregated output. For example:
+
+	test_perf 'time foo' '
+		./foo >foo.out
+	'
+
+	test_size 'output size'
+		wc -c <foo.out
+	'
+
+might produce output like:
+
+	Test                origin           HEAD
+	-------------------------------------------------------------
+	1234.1 time foo     0.37(0.79+0.02)  0.26(0.51+0.02) -29.7%
+	1234.2 output size             4.3M             3.6M -14.7%
+
+The item being measured (and its units) is up to the test; the context
+and the test title should make it clear to the user whether bigger or
+smaller numbers are better. Unlike test_perf, the test code will only be
+run once, since output sizes tend to be more deterministic than timings.
diff --git a/t/perf/aggregate.perl b/t/perf/aggregate.perl
index 1dbc85b214..494907a892 100755
--- a/t/perf/aggregate.perl
+++ b/t/perf/aggregate.perl
@@ -1,8 +1,10 @@
 #!/usr/bin/perl
 
-use lib '../../perl/blib/lib';
+use lib '../../perl/build/lib';
 use strict;
 use warnings;
+use JSON;
+use Getopt::Long;
 use Git;
 
 sub get_times {
@@ -11,31 +13,89 @@ sub get_times {
 	my $line = <$fh>;
 	return undef if not defined $line;
 	close $fh or die "cannot close $name: $!";
-	$line =~ /^(?:(\d+):)?(\d+):(\d+(?:\.\d+)?) (\d+(?:\.\d+)?) (\d+(?:\.\d+)?)$/
-		or die "bad input line: $line";
-	my $rt = ((defined $1 ? $1 : 0.0)*60+$2)*60+$3;
-	return ($rt, $4, $5);
+	# times
+	if ($line =~ /^(?:(\d+):)?(\d+):(\d+(?:\.\d+)?) (\d+(?:\.\d+)?) (\d+(?:\.\d+)?)$/) {
+		my $rt = ((defined $1 ? $1 : 0.0)*60+$2)*60+$3;
+		return ($rt, $4, $5);
+	# size
+	} elsif ($line =~ /^\d+$/) {
+		return $&;
+	} else {
+		die "bad input line: $line";
+	}
+}
+
+sub relative_change {
+	my ($r, $firstr) = @_;
+	if ($firstr > 0) {
+		return sprintf "%+.1f%%", 100.0*($r-$firstr)/$firstr;
+	} elsif ($r == 0) {
+		return "=";
+	} else {
+		return "+inf";
+	}
 }
 
 sub format_times {
 	my ($r, $u, $s, $firstr) = @_;
+	# no value means we did not finish the test
 	if (!defined $r) {
 		return "<missing>";
 	}
+	# a single value means we have a size, not times
+	if (!defined $u) {
+		return format_size($r, $firstr);
+	}
+	# otherwise, we have real/user/system times
 	my $out = sprintf "%.2f(%.2f+%.2f)", $r, $u, $s;
-	if (defined $firstr) {
-		if ($firstr > 0) {
-			$out .= sprintf " %+.1f%%", 100.0*($r-$firstr)/$firstr;
-		} elsif ($r == 0) {
-			$out .= " =";
-		} else {
-			$out .= " +inf";
-		}
+	$out .= ' ' . relative_change($r, $firstr) if defined $firstr;
+	return $out;
+}
+
+sub usage {
+	print <<EOT;
+./aggregate.perl [options] [--] [<dir_or_rev>...] [--] [<test_script>...] >
+
+  Options:
+    --codespeed          * Format output for Codespeed
+    --reponame    <str>  * Send given reponame to codespeed
+    --sort-by     <str>  * Sort output (only "regression" criteria is supported)
+    --subsection  <str>  * Use results from given subsection
+
+EOT
+	exit(1);
+}
+
+sub human_size {
+	my $n = shift;
+	my @units = ('', qw(K M G));
+	while ($n > 900 && @units > 1) {
+		$n /= 1000;
+		shift @units;
 	}
+	return $n unless length $units[0];
+	return sprintf '%.1f%s', $n, $units[0];
+}
+
+sub format_size {
+	my ($size, $first) = @_;
+	# match the width of a time: 0.00(0.00+0.00)
+	my $out = sprintf '%15s', human_size($size);
+	$out .= ' ' . relative_change($size, $first) if defined $first;
 	return $out;
 }
 
-my (@dirs, %dirnames, %dirabbrevs, %prefixes, @tests);
+my (@dirs, %dirnames, %dirabbrevs, %prefixes, @tests,
+    $codespeed, $sortby, $subsection, $reponame);
+
+Getopt::Long::Configure qw/ require_order /;
+
+my $rc = GetOptions("codespeed"     => \$codespeed,
+		    "reponame=s"    => \$reponame,
+		    "sort-by=s"     => \$sortby,
+		    "subsection=s"  => \$subsection);
+usage() unless $rc;
+
 while (scalar @ARGV) {
 	my $arg = $ARGV[0];
 	my $dir;
@@ -69,12 +129,24 @@ if (not @tests) {
 	@tests = glob "p????-*.sh";
 }
 
+my $resultsdir = "test-results";
+
+if (! $subsection and
+    exists $ENV{GIT_PERF_SUBSECTION} and
+    $ENV{GIT_PERF_SUBSECTION} ne "") {
+	$subsection = $ENV{GIT_PERF_SUBSECTION};
+}
+
+if ($subsection) {
+	$resultsdir .= "/" . $subsection;
+}
+
 my @subtests;
 my %shorttests;
 for my $t (@tests) {
 	$t =~ s{(?:.*/)?(p(\d+)-[^/]+)\.sh$}{$1} or die "bad test name: $t";
 	my $n = $2;
-	my $fname = "test-results/$t.subtests";
+	my $fname = "$resultsdir/$t.subtests";
 	open my $fp, "<", $fname or die "cannot open $fname: $!";
 	for (<$fp>) {
 		chomp;
@@ -95,13 +167,6 @@ sub read_descr {
 	return $line;
 }
 
-my %descrs;
-my $descrlen = 4; # "Test"
-for my $t (@subtests) {
-	$descrs{$t} = $shorttests{$t}.": ".read_descr("test-results/$t.descr");
-	$descrlen = length $descrs{$t} if length $descrs{$t}>$descrlen;
-}
-
 sub have_duplicate {
 	my %seen;
 	for (@_) {
@@ -117,54 +182,175 @@ sub have_slash {
 	return 0;
 }
 
-my %newdirabbrevs = %dirabbrevs;
-while (!have_duplicate(values %newdirabbrevs)) {
-	%dirabbrevs = %newdirabbrevs;
-	last if !have_slash(values %dirabbrevs);
-	%newdirabbrevs = %dirabbrevs;
-	for (values %newdirabbrevs) {
-		s{^[^/]*/}{};
-	}
+sub display_dir {
+	my ($d) = @_;
+	return exists $dirabbrevs{$d} ? $dirabbrevs{$d} : $dirnames{$d};
 }
 
-my %times;
-my @colwidth = ((0)x@dirs);
-for my $i (0..$#dirs) {
-	my $d = $dirs[$i];
-	my $w = length (exists $dirabbrevs{$d} ? $dirabbrevs{$d} : $dirnames{$d});
-	$colwidth[$i] = $w if $w > $colwidth[$i];
-}
-for my $t (@subtests) {
-	my $firstr;
+sub print_default_results {
+	my %descrs;
+	my $descrlen = 4; # "Test"
+	for my $t (@subtests) {
+		$descrs{$t} = $shorttests{$t}.": ".read_descr("$resultsdir/$t.descr");
+		$descrlen = length $descrs{$t} if length $descrs{$t}>$descrlen;
+	}
+
+	my %newdirabbrevs = %dirabbrevs;
+	while (!have_duplicate(values %newdirabbrevs)) {
+		%dirabbrevs = %newdirabbrevs;
+		last if !have_slash(values %dirabbrevs);
+		%newdirabbrevs = %dirabbrevs;
+		for (values %newdirabbrevs) {
+			s{^[^/]*/}{};
+		}
+	}
+
+	my %times;
+	my @colwidth = ((0)x@dirs);
 	for my $i (0..$#dirs) {
-		my $d = $dirs[$i];
-		$times{$prefixes{$d}.$t} = [get_times("test-results/$prefixes{$d}$t.times")];
-		my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
-		my $w = length format_times($r,$u,$s,$firstr);
+		my $w = length display_dir($dirs[$i]);
 		$colwidth[$i] = $w if $w > $colwidth[$i];
-		$firstr = $r unless defined $firstr;
+	}
+	for my $t (@subtests) {
+		my $firstr;
+		for my $i (0..$#dirs) {
+			my $d = $dirs[$i];
+			my $base = "$resultsdir/$prefixes{$d}$t";
+			$times{$prefixes{$d}.$t} = [];
+			foreach my $type (qw(times size)) {
+				if (-e "$base.$type") {
+					$times{$prefixes{$d}.$t} = [get_times("$base.$type")];
+					last;
+				}
+			}
+			my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
+			my $w = length format_times($r,$u,$s,$firstr);
+			$colwidth[$i] = $w if $w > $colwidth[$i];
+			$firstr = $r unless defined $firstr;
+		}
+	}
+	my $totalwidth = 3*@dirs+$descrlen;
+	$totalwidth += $_ for (@colwidth);
+
+	printf "%-${descrlen}s", "Test";
+	for my $i (0..$#dirs) {
+		printf "   %-$colwidth[$i]s", display_dir($dirs[$i]);
+	}
+	print "\n";
+	print "-"x$totalwidth, "\n";
+	for my $t (@subtests) {
+		printf "%-${descrlen}s", $descrs{$t};
+		my $firstr;
+		for my $i (0..$#dirs) {
+			my $d = $dirs[$i];
+			my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
+			printf "   %-$colwidth[$i]s", format_times($r,$u,$s,$firstr);
+			$firstr = $r unless defined $firstr;
+		}
+		print "\n";
 	}
 }
-my $totalwidth = 3*@dirs+$descrlen;
-$totalwidth += $_ for (@colwidth);
 
-binmode STDOUT, ":utf8" or die "PANIC on binmode: $!";
+sub print_sorted_results {
+	my ($sortby) = @_;
 
-printf "%-${descrlen}s", "Test";
-for my $i (0..$#dirs) {
-	my $d = $dirs[$i];
-	printf "   %-$colwidth[$i]s", (exists $dirabbrevs{$d} ? $dirabbrevs{$d} : $dirnames{$d});
+	if ($sortby ne "regression") {
+		print "Only 'regression' is supported as '--sort-by' argument\n";
+		usage();
+	}
+
+	my @evolutions;
+	for my $t (@subtests) {
+		my ($prevr, $prevu, $prevs, $prevrev);
+		for my $i (0..$#dirs) {
+			my $d = $dirs[$i];
+			my ($r, $u, $s) = get_times("$resultsdir/$prefixes{$d}$t.times");
+			if ($i > 0 and defined $r and defined $prevr and $prevr > 0) {
+				my $percent = 100.0 * ($r - $prevr) / $prevr;
+				push @evolutions, { "percent"  => $percent,
+						    "test"     => $t,
+						    "prevrev"  => $prevrev,
+						    "rev"      => $d,
+						    "prevr"    => $prevr,
+						    "r"        => $r,
+						    "prevu"    => $prevu,
+						    "u"        => $u,
+						    "prevs"    => $prevs,
+						    "s"        => $s};
+			}
+			($prevr, $prevu, $prevs, $prevrev) = ($r, $u, $s, $d);
+		}
+	}
+
+	my @sorted_evolutions = sort { $b->{percent} <=> $a->{percent} } @evolutions;
+
+	for my $e (@sorted_evolutions) {
+		printf "%+.1f%%", $e->{percent};
+		print " " . $e->{test};
+		print " " . format_times($e->{prevr}, $e->{prevu}, $e->{prevs});
+		print " " . format_times($e->{r}, $e->{u}, $e->{s});
+		print " " . display_dir($e->{prevrev});
+		print " " . display_dir($e->{rev});
+		print "\n";
+	}
 }
-print "\n";
-print "-"x$totalwidth, "\n";
-for my $t (@subtests) {
-	printf "%-${descrlen}s", $descrs{$t};
-	my $firstr;
-	for my $i (0..$#dirs) {
-		my $d = $dirs[$i];
-		my ($r,$u,$s) = @{$times{$prefixes{$d}.$t}};
-		printf "   %-$colwidth[$i]s", format_times($r,$u,$s,$firstr);
-		$firstr = $r unless defined $firstr;
+
+sub print_codespeed_results {
+	my ($subsection) = @_;
+
+	my $project = "Git";
+
+	my $executable = `uname -s -m`;
+	chomp $executable;
+
+	if ($subsection) {
+		$executable .= ", " . $subsection;
 	}
-	print "\n";
+
+	my $environment;
+	if ($reponame) {
+		$environment = $reponame;
+	} elsif (exists $ENV{GIT_PERF_REPO_NAME} and $ENV{GIT_PERF_REPO_NAME} ne "") {
+		$environment = $ENV{GIT_PERF_REPO_NAME};
+	} elsif (exists $ENV{GIT_TEST_INSTALLED} and $ENV{GIT_TEST_INSTALLED} ne "") {
+		$environment = $ENV{GIT_TEST_INSTALLED};
+		$environment =~ s|/bin-wrappers$||;
+	} else {
+		$environment = `uname -r`;
+		chomp $environment;
+	}
+
+	my @data;
+
+	for my $t (@subtests) {
+		for my $d (@dirs) {
+			my $commitid = $prefixes{$d};
+			$commitid =~ s/^build_//;
+			$commitid =~ s/\.$//;
+			my ($result_value, $u, $s) = get_times("$resultsdir/$prefixes{$d}$t.times");
+
+			my %vals = (
+				"commitid" => $commitid,
+				"project" => $project,
+				"branch" => $dirnames{$d},
+				"executable" => $executable,
+				"benchmark" => $shorttests{$t} . " " . read_descr("$resultsdir/$t.descr"),
+				"environment" => $environment,
+				"result_value" => $result_value,
+			    );
+			push @data, \%vals;
+		}
+	}
+
+	print to_json(\@data, {utf8 => 1, pretty => 1, canonical => 1}), "\n";
+}
+
+binmode STDOUT, ":utf8" or die "PANIC on binmode: $!";
+
+if ($codespeed) {
+	print_codespeed_results($subsection);
+} elsif (defined $sortby) {
+	print_sorted_results($sortby);
+} else {
+	print_default_results();
 }
diff --git a/t/perf/bisect_regression b/t/perf/bisect_regression
new file mode 100755
index 0000000000..a94d9955d0
--- /dev/null
+++ b/t/perf/bisect_regression
@@ -0,0 +1,73 @@
+#!/bin/sh
+
+# Read a line coming from `./aggregate.perl --sort-by regression ...`
+# and automatically bisect to find the commit responsible for the
+# performance regression.
+#
+# Lines from `./aggregate.perl --sort-by regression ...` look like:
+#
+# +100.0% p7821-grep-engines-fixed.1 0.04(0.10+0.03) 0.08(0.11+0.08) v2.14.3 v2.15.1
+# +33.3% p7820-grep-engines.1 0.03(0.08+0.02) 0.04(0.08+0.02) v2.14.3 v2.15.1
+#
+
+die () {
+	echo >&2 "error: $*"
+	exit 1
+}
+
+while [ $# -gt 0 ]; do
+	arg="$1"
+	case "$arg" in
+	--help)
+		echo "usage: $0 [--config file] [--subsection subsection]"
+		exit 0
+		;;
+	--config)
+		shift
+		GIT_PERF_CONFIG_FILE=$(cd "$(dirname "$1")"; pwd)/$(basename "$1")
+		export GIT_PERF_CONFIG_FILE
+		shift ;;
+	--subsection)
+		shift
+		GIT_PERF_SUBSECTION="$1"
+		export GIT_PERF_SUBSECTION
+		shift ;;
+	--*)
+		die "unrecognised option: '$arg'" ;;
+	*)
+		die "unknown argument '$arg'"
+		;;
+	esac
+done
+
+read -r regression subtest oldtime newtime oldrev newrev
+
+test_script=$(echo "$subtest" | sed -e 's/\(.*\)\.[0-9]*$/\1.sh/')
+test_number=$(echo "$subtest" | sed -e 's/.*\.\([0-9]*\)$/\1/')
+
+# oldtime and newtime are decimal number, not integers
+
+oldtime=$(echo "$oldtime" | sed -e 's/^\([0-9]\+\.[0-9]\+\).*$/\1/')
+newtime=$(echo "$newtime" | sed -e 's/^\([0-9]\+\.[0-9]\+\).*$/\1/')
+
+test $(echo "$newtime" "$oldtime" | awk '{ print ($1 > $2) }') = 1 ||
+	die "New time '$newtime' shoud be greater than old time '$oldtime'"
+
+tmpdir=$(mktemp -d -t bisect_regression_XXXXXX) || die "Failed to create temp directory"
+echo "$oldtime" >"$tmpdir/oldtime" || die "Failed to write to '$tmpdir/oldtime'"
+echo "$newtime" >"$tmpdir/newtime" || die "Failed to write to '$tmpdir/newtime'"
+
+# Bisecting must be performed from the top level directory (even with --no-checkout)
+(
+	toplevel_dir=$(git rev-parse --show-toplevel) || die "Failed to find top level directory"
+	cd "$toplevel_dir" || die "Failed to cd into top level directory '$toplevel_dir'"
+
+	git bisect start --no-checkout "$newrev" "$oldrev" || die "Failed to start bisecting"
+
+	git bisect run t/perf/bisect_run_script "$test_script" "$test_number" "$tmpdir"
+	res="$?"
+
+	git bisect reset
+
+	exit "$res"
+)
diff --git a/t/perf/bisect_run_script b/t/perf/bisect_run_script
new file mode 100755
index 0000000000..3ebaf15521
--- /dev/null
+++ b/t/perf/bisect_run_script
@@ -0,0 +1,53 @@
+#!/bin/sh
+
+script="$1"
+test_number="$2"
+info_dir="$3"
+
+# This aborts the bisection immediately
+die () {
+	echo >&2 "error: $*"
+	exit 255
+}
+
+bisect_head=$(git rev-parse --verify BISECT_HEAD) || die "Failed to find BISECT_HEAD ref"
+
+script_number=$(echo "$script" | sed -e "s/^p\([0-9]*\).*\$/\1/") || die "Failed to get script number for '$script'"
+
+oldtime=$(cat "$info_dir/oldtime") || die "Failed to access '$info_dir/oldtime'"
+newtime=$(cat "$info_dir/newtime") || die "Failed to access '$info_dir/newtime'"
+
+cd t/perf || die "Failed to cd into 't/perf'"
+
+result_file="$info_dir/perf_${script_number}_${bisect_head}_results.txt"
+
+GIT_PERF_DIRS_OR_REVS="$bisect_head"
+export GIT_PERF_DIRS_OR_REVS
+
+# Don't use codespeed
+GIT_PERF_CODESPEED_OUTPUT=
+GIT_PERF_SEND_TO_CODESPEED=
+export GIT_PERF_CODESPEED_OUTPUT
+export GIT_PERF_SEND_TO_CODESPEED
+
+./run "$script" >"$result_file" 2>&1 || die "Failed to run perf test '$script'"
+
+rtime=$(sed -n "s/^$script_number\.$test_number:.*\([0-9]\+\.[0-9]\+\)(.*).*\$/\1/p" "$result_file")
+
+echo "newtime: $newtime"
+echo "rtime: $rtime"
+echo "oldtime: $oldtime"
+
+# Compare ($newtime - $rtime) with ($rtime - $oldtime)
+# Times are decimal number, not integers
+
+if test $(echo "$newtime" "$rtime" "$oldtime" | awk '{ print ($1 - $2 > $2 - $3) }') = 1
+then
+	# Current commit is considered "good/old"
+	echo "$rtime" >"$info_dir/oldtime"
+	exit 0
+else
+	# Current commit is considered "bad/new"
+	echo "$rtime" >"$info_dir/newtime"
+	exit 1
+fi
diff --git a/t/perf/lib-pack.sh b/t/perf/lib-pack.sh
new file mode 100644
index 0000000000..d3865db286
--- /dev/null
+++ b/t/perf/lib-pack.sh
@@ -0,0 +1,25 @@
+# Helpers for dealing with large numbers of packs.
+
+# create $1 nonsense packs, each with a single blob
+create_packs () {
+	perl -le '
+		my ($n) = @ARGV;
+		for (1..$n) {
+			print "blob";
+			print "data <<EOF";
+			print "$_";
+			print "EOF";
+			print "checkpoint"
+		}
+	' "$@" |
+	git fast-import
+}
+
+# create a large number of packs, disabling any gc which might
+# cause us to repack them
+setup_many_packs () {
+	git config gc.auto 0 &&
+	git config gc.autopacklimit 0 &&
+	git config fastimport.unpacklimit 0 &&
+	create_packs 500
+}
diff --git a/t/perf/p0002-read-cache.sh b/t/perf/p0002-read-cache.sh
index 9180ae9343..cdd105a594 100755
--- a/t/perf/p0002-read-cache.sh
+++ b/t/perf/p0002-read-cache.sh
@@ -8,7 +8,7 @@ test_perf_default_repo
 
 count=1000
 test_perf "read_cache/discard_cache $count times" "
-	test-read-cache $count
+	test-tool read-cache $count
 "
 
 test_done
diff --git a/t/perf/p0004-lazy-init-name-hash.sh b/t/perf/p0004-lazy-init-name-hash.sh
index 8de5a98cfc..1afc08fe7f 100755
--- a/t/perf/p0004-lazy-init-name-hash.sh
+++ b/t/perf/p0004-lazy-init-name-hash.sh
@@ -7,8 +7,8 @@ test_perf_large_repo
 test_checkout_worktree
 
 test_expect_success 'verify both methods build the same hashmaps' '
-	test-lazy-init-name-hash --dump --single >out.single &&
-	if test-lazy-init-name-hash --dump --multi >out.multi
+	test-tool lazy-init-name-hash --dump --single >out.single &&
+	if test-tool lazy-init-name-hash --dump --multi >out.multi
 	then
 		test_set_prereq REPO_BIG_ENOUGH_FOR_MULTI &&
 		sort <out.single >sorted.single &&
@@ -46,11 +46,11 @@ test_expect_success 'calibrate' '
 '
 
 test_perf "single-threaded, $desc" "
-	test-lazy-init-name-hash --single --count=$count
+	test-tool lazy-init-name-hash --single --count=$count
 "
 
 test_perf REPO_BIG_ENOUGH_FOR_MULTI "multi-threaded, $desc" "
-	test-lazy-init-name-hash --multi --count=$count
+	test-tool lazy-init-name-hash --multi --count=$count
 "
 
 test_done
diff --git a/t/perf/p0007-write-cache.sh b/t/perf/p0007-write-cache.sh
new file mode 100755
index 0000000000..09595264f0
--- /dev/null
+++ b/t/perf/p0007-write-cache.sh
@@ -0,0 +1,29 @@
+#!/bin/sh
+
+test_description="Tests performance of writing the index"
+
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+test_expect_success "setup repo" '
+	if git rev-parse --verify refs/heads/p0006-ballast^{commit}
+	then
+		echo Assuming synthetic repo from many-files.sh
+		git config --local core.sparsecheckout 1
+		cat >.git/info/sparse-checkout <<-EOF
+		/*
+		!ballast/*
+		EOF
+	else
+		echo Assuming non-synthetic repo...
+	fi &&
+	nr_files=$(git ls-files | wc -l)
+'
+
+count=3
+test_perf "write_locked_index $count times ($nr_files files)" "
+	test-tool write-cache $count
+"
+
+test_done
diff --git a/t/perf/p0071-sort.sh b/t/perf/p0071-sort.sh
index 7c9a35a646..6e924f5fa3 100755
--- a/t/perf/p0071-sort.sh
+++ b/t/perf/p0071-sort.sh
@@ -16,7 +16,7 @@ test_perf 'sort(1)' '
 '
 
 test_perf 'string_list_sort()' '
-	test-string-list sort <unsorted >actual
+	test-tool string-list sort <unsorted >actual
 '
 
 test_expect_success 'string_list_sort() sorts like sort(1)' '
diff --git a/t/perf/p1450-fsck.sh b/t/perf/p1450-fsck.sh
new file mode 100755
index 0000000000..ae1b84198b
--- /dev/null
+++ b/t/perf/p1450-fsck.sh
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+test_description='Test fsck performance'
+
+. ./perf-lib.sh
+
+test_perf_large_repo
+
+test_perf 'fsck' '
+	git fsck
+'
+
+test_done
diff --git a/t/perf/p1451-fsck-skip-list.sh b/t/perf/p1451-fsck-skip-list.sh
new file mode 100755
index 0000000000..c2b97d2487
--- /dev/null
+++ b/t/perf/p1451-fsck-skip-list.sh
@@ -0,0 +1,40 @@
+#!/bin/sh
+
+test_description='Test fsck skipList performance'
+
+. ./perf-lib.sh
+
+test_perf_fresh_repo
+
+n=1000000
+
+test_expect_success "setup $n bad commits" '
+	for i in $(test_seq 1 $n)
+	do
+		echo "commit refs/heads/master" &&
+		echo "committer C <c@example.com> 1234567890 +0000" &&
+		echo "data <<EOF" &&
+		echo "$i.Q." &&
+		echo "EOF"
+	done | q_to_nul | git fast-import
+'
+
+skip=0
+while test $skip -le $n
+do
+	test_expect_success "create skipList for $skip bad commits" '
+		git log --format=%H --max-count=$skip |
+		sort >skiplist
+	'
+
+	test_perf "fsck with $skip skipped bad commits" '
+		git -c fsck.skipList=skiplist fsck
+	'
+
+	case $skip in
+	0) skip=1 ;;
+	*) skip=${skip}0 ;;
+	esac
+done
+
+test_done
diff --git a/t/perf/p3400-rebase.sh b/t/perf/p3400-rebase.sh
index ce271ca4c1..d202aaed06 100755
--- a/t/perf/p3400-rebase.sh
+++ b/t/perf/p3400-rebase.sh
@@ -6,9 +6,9 @@ test_description='Tests rebase performance'
 test_perf_default_repo
 
 test_expect_success 'setup rebasing on top of a lot of changes' '
-	git checkout -f -b base &&
-	git checkout -b to-rebase &&
-	git checkout -b upstream &&
+	git checkout -f -B base &&
+	git checkout -B to-rebase &&
+	git checkout -B upstream &&
 	for i in $(seq 100)
 	do
 		# simulate huge diffs
@@ -35,8 +35,8 @@ test_perf 'rebase on top of a lot of unrelated changes' '
 
 test_expect_success 'setup rebasing many changes without split-index' '
 	git config core.splitIndex false &&
-	git checkout -b upstream2 to-rebase &&
-	git checkout -b to-rebase2 upstream
+	git checkout -B upstream2 to-rebase &&
+	git checkout -B to-rebase2 upstream
 '
 
 test_perf 'rebase a lot of unrelated changes without split-index' '
diff --git a/t/perf/p4211-line-log.sh b/t/perf/p4211-line-log.sh
index b7ff68d4fa..392bcc0e51 100755
--- a/t/perf/p4211-line-log.sh
+++ b/t/perf/p4211-line-log.sh
@@ -31,4 +31,12 @@ test_perf 'git log -L (renames on)' '
 	git log -M -L 1:"$file" >/dev/null
 '
 
+test_perf 'git log --oneline --raw --parents' '
+	git log --oneline --raw --parents >/dev/null
+'
+
+test_perf 'git log --oneline --raw --parents -1000' '
+	git log --oneline --raw --parents -1000 >/dev/null
+'
+
 test_done
diff --git a/t/perf/p5311-pack-bitmaps-fetch.sh b/t/perf/p5311-pack-bitmaps-fetch.sh
new file mode 100755
index 0000000000..b04575951f
--- /dev/null
+++ b/t/perf/p5311-pack-bitmaps-fetch.sh
@@ -0,0 +1,45 @@
+#!/bin/sh
+
+test_description='performance of fetches from bitmapped packs'
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+test_expect_success 'create bitmapped server repo' '
+	git config pack.writebitmaps true &&
+	git config pack.writebitmaphashcache true &&
+	git repack -ad
+'
+
+# simulate a fetch from a repository that last fetched N days ago, for
+# various values of N. We do so by following the first-parent chain,
+# and assume the first entry in the chain that is N days older than the current
+# HEAD is where the HEAD would have been then.
+for days in 1 2 4 8 16 32 64 128; do
+	title=$(printf '%10s' "($days days)")
+	test_expect_success "setup revs from $days days ago" '
+		now=$(git log -1 --format=%ct HEAD) &&
+		then=$(($now - ($days * 86400))) &&
+		tip=$(git rev-list -1 --first-parent --until=$then HEAD) &&
+		{
+			echo HEAD &&
+			echo ^$tip
+		} >revs
+	'
+
+	test_perf "server $title" '
+		git pack-objects --stdout --revs \
+				 --thin --delta-base-offset \
+				 <revs >tmp.pack
+	'
+
+	test_size "size   $title" '
+		wc -c <tmp.pack
+	'
+
+	test_perf "client $title" '
+		git index-pack --stdin --fix-thin <tmp.pack
+	'
+done
+
+test_done
diff --git a/t/perf/p5550-fetch-tags.sh b/t/perf/p5550-fetch-tags.sh
index a5dc39f86a..d0e0e019ea 100755
--- a/t/perf/p5550-fetch-tags.sh
+++ b/t/perf/p5550-fetch-tags.sh
@@ -20,6 +20,7 @@ start to show a noticeable performance problem on my machine, but without
 taking too long to set up and run the tests.
 '
 . ./perf-lib.sh
+. "$TEST_DIRECTORY/perf/lib-pack.sh"
 
 # make a long nonsense history on branch $1, consisting of $2 commits, each
 # with a unique file pointing to the blob at $2.
@@ -44,26 +45,6 @@ create_tags () {
 	git update-ref --stdin
 }
 
-# create $1 nonsense packs, each with a single blob
-create_packs () {
-	perl -le '
-		my ($n) = @ARGV;
-		for (1..$n) {
-			print "blob";
-			print "data <<EOF";
-			print "$_";
-			print "EOF";
-		}
-	' "$@" |
-	git fast-import &&
-
-	git cat-file --batch-all-objects --batch-check='%(objectname)' |
-	while read sha1
-	do
-		echo $sha1 | git pack-objects .git/objects/pack/pack
-	done
-}
-
 test_expect_success 'create parent and child' '
 	git init parent &&
 	git -C parent commit --allow-empty -m base &&
@@ -84,9 +65,7 @@ test_expect_success 'populate parent tags' '
 test_expect_success 'create child packs' '
 	(
 		cd child &&
-		git config gc.auto 0 &&
-		git config gc.autopacklimit 0 &&
-		create_packs 500
+		setup_many_packs
 	)
 '
 
diff --git a/t/perf/p5551-fetch-rescan.sh b/t/perf/p5551-fetch-rescan.sh
new file mode 100755
index 0000000000..b99dc23e32
--- /dev/null
+++ b/t/perf/p5551-fetch-rescan.sh
@@ -0,0 +1,55 @@
+#!/bin/sh
+
+test_description='fetch performance with many packs
+
+It is common for fetch to consider objects that we might not have, and it is an
+easy mistake for the code to use a function like `parse_object` that might
+give the correct _answer_ on such an object, but do so slowly (due to
+re-scanning the pack directory for lookup failures).
+
+The resulting performance drop can be hard to notice in a real repository, but
+becomes quite large in a repository with a large number of packs. So this
+test creates a more pathological case, since any mistakes would produce a more
+noticeable slowdown.
+'
+. ./perf-lib.sh
+. "$TEST_DIRECTORY"/perf/lib-pack.sh
+
+test_expect_success 'create parent and child' '
+	git init parent &&
+	git clone parent child
+'
+
+
+test_expect_success 'create refs in the parent' '
+	(
+		cd parent &&
+		git commit --allow-empty -m foo &&
+		head=$(git rev-parse HEAD) &&
+		test_seq 1000 |
+		sed "s,.*,update refs/heads/& $head," |
+		$MODERN_GIT update-ref --stdin
+	)
+'
+
+test_expect_success 'create many packs in the child' '
+	(
+		cd child &&
+		setup_many_packs
+	)
+'
+
+test_perf 'fetch' '
+	# start at the same state for each iteration
+	obj=$($MODERN_GIT -C parent rev-parse HEAD) &&
+	(
+		cd child &&
+		$MODERN_GIT for-each-ref --format="delete %(refname)" refs/remotes |
+		$MODERN_GIT update-ref --stdin &&
+		rm -vf .git/objects/$(echo $obj | sed "s|^..|&/|") &&
+
+		git fetch
+	)
+'
+
+test_done
diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
new file mode 100755
index 0000000000..def7ecdbc7
--- /dev/null
+++ b/t/perf/p7519-fsmonitor.sh
@@ -0,0 +1,183 @@
+#!/bin/sh
+
+test_description="Test core.fsmonitor"
+
+. ./perf-lib.sh
+
+#
+# Performance test for the fsmonitor feature which enables git to talk to a
+# file system change monitor and avoid having to scan the working directory
+# for new or modified files.
+#
+# By default, the performance test will utilize the Watchman file system
+# monitor if it is installed.  If Watchman is not installed, it will use a
+# dummy integration script that does not report any new or modified files.
+# The dummy script has very little overhead which provides optimistic results.
+#
+# The performance test will also use the untracked cache feature if it is
+# available as fsmonitor uses it to speed up scanning for untracked files.
+#
+# There are 3 environment variables that can be used to alter the default
+# behavior of the performance test:
+#
+# GIT_PERF_7519_UNTRACKED_CACHE: used to configure core.untrackedCache
+#